Fine structure and high intensity of photoluminescence from Er doped in Ni-Si-O compounds

Er3+ doped Ni-Si-O compounds deposited by the magnetron sputtering technique are investigated. Compared with the optimized photoluminescence (PL) of Er3+ in Si-rich Si oxide, the PL of Er3+ in the compounds is strikingly enhanced in the ranges 500-900 nm and 1470-1650 nm. This enhancement and the appearance of many sharp peaks around 1.54 μm in the spectra depend on the Ni content and the annealing temperature. Two-order enhancement in the range 1470-1650 nm is achieved for the Ni-Si-O compound with 25 at.% Ni after 1150 deg. C annealing. The above experiments indicate that Ni induces new local environments around Er3+, which are responsible for PL enhancement and appearance of sharp peaks.